Control element for hydraulic cylinders

ABSTRACT

A control element for hydraulic cylinders particularly adapted for actuating working tools mounted on earth-moving machines and the like, wherein the front end of the control element is hydraulically biased against the force of springs to maintain the control element in a neutral position. In order to limit the stroke of the ends of the control element, pistons are provided at the ends which have a diameter larger than a diameter of the ends of the control element, and are displaced longitudinally between a pair of limits within variable springs. The springs are also supported between the inner side of the pistons and supports and caps, loosely placed over the ends of the control element. The caps serve as a collar or strap so that the ends are longitudinally displaced with respect to the control element housing.

United States Patent UNITED STATES PATENTS 1,787,328 12/1930 Schottler 2,157,240 5/1939 Keel 1/167 X 2,826,178 3/1958 Krapf l37/625.63 2,836,196 5/1958 Gunn l37/596. 16 3,320,745 5/l967 Buhniuk et al.. 91/461 3,533,440 10/1970 Berry 137/59618 Primary Examiner-M. Cary Nelson Assistant Examiner- Robert J. Miller AltomeyAllis0n C1 Collard ABSTRACT: A control element for hydraulic cylinders particularly adapted for actuating working tools mounted on PATENTEDHUV 30 I9?! SHEET 1 OF 3 INVENTOR EDMUND VOGG WILHELM R BY I Attorney PATENTED NOV 3 0 l97l SHEET 2 BF 3 INVENTOR EDMUND VOGG WILHELM RENNER QALQ QAJQ QQ Attorney PATENTEUHUV 3019?: 3 623 507' SHEET 3 OF 3 Fig. 3

INVENTOR EDMUND VOGG BY WILHESI I Attorney This invention relates to a control element for hydraulic cylinders.

In accordance with the invention, only the outer ends of the pistons are fed with hydraulic fluid if the control element is movement takes place on the other side of the neutral position.

It is, therefore, an object according to the present invention to provide a control element for hydraulic cylinders which inple in design, inexpensive to manufacture, and reliable in operation.

become apparent from the following detailed description conderstood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows the neutral position of the control element;

FIG. 2 shows the first switching position of the control element; and

FIG. 3 shows the second switching position of the control element.

Referring to FIG. 1-3, a control element 1 is mounted in housing 2 to control certain main and branch feeder lines a, b, c, d, e, f, g, and h, which for the purpose of subject invention The extreme ends 1 of control element 1 are arranged as plunger pistons ll'l variable cylinders 8. Caps 9, which are provided with openings 9, are positioned on top of ends 1. Collars, straps, and the like, may be also used. Springs 10 press bearing shoulders 9" of caps against the outer front walls of of pistons 11. Pistons II are displaceable longitudinally in variable cylinders 8, between inner abutments l2 and outer abutments 13. It should be noted that pistons 11 have a larger diameter than front ends 1' of control element 1. As can be seen in FIG. I, in the zero position, pistons 11 are fed by hydraulic fluid under pressure, on their outer front face and are therefore held in a fixed position against inner abutments 12.

The inner bottom sides of caps 9 retain control element 1 in a fixed position on its outer front faces, since the plunger spaces of front ends 9' are not fed by hydraulic fluid under pressure.

In the first switching position I as shown in FIG. 2, the upper plunger space is fed by hydraulic fluid under pressure through line 15, while the hydraulic pressure can escape from the lower plunger space through line 16. Everything else, however, remains as shown in F IG. 1. Accordingly, the upper front end 1 of control element 1, is moved downward until its lower front face, together with its associated cap and spring, engage type of function and operation.

While only a single embodiment of the present invention has been shown and descnbed, it will be obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.

What is claimed is:

l. A control apparatus for hydraulic cylinders operated by a hydraulic fluid under pressure comprising;

an elongated hollow control element housing having cylinder on each end,

an elongated control element slidably disposed within said housing, said cylinders including fluid-receiving apertures communicative with the ends of said control element,

a piston disposed in each cylinder of said housing,

an open cap disposed over each end of said control element within said cylinders,

spring means for spring biasing said caps with respect to said pistons, said control element having a neutral position when hydraulic fluid is fed under pressure through said apertures to the top of each of said pistons in said cylinders,

a first position when hydraulic fluid is additionally fed to one of said caps while being withdrawn from the other of said caps, and

a second position when hydraulic fluid is removed from the top of additionally said piston adjacent to the cap having the withdrawn fluid.

2. The control caps include ape apparatus as recited in claim 1, wherein said rtures communicative between the ends of 

1. A control apparatus for hydraulic cylinders operated by a hydraulic fluid under pressure comprising; an elongated hollow control element housing having cylinders on each end, an elongated control element slidably disposed within said housing, said cylinders including fluid-receiving apertures communicative with the ends of said control element, a piston disposed in each cylinder of said housing, an open cap disposed over each end of said control element within said cylinders, spring means for spring biasing said caps with respect to said pistons, said control element having a neutral position when hydraulic fluid is fed under pressure through said apertures to the top of each of said pistons in said cylinders, a first position when hydraulic fluid is additionally fed to one of said caps while being withdrawn from the other of said caps, and a second position when hydraulic fluid is additionally removed from the top of said piston adjacent to the cap having the withdrawn fluid.
 2. The control apparatus as recited in claim 1, wherein said caps include apertures communicative between the ends of said control element and said pistons, said caps further comprising external flanges for supporting said spring means against the bottom surfaces of said pistons in said cylinders.
 3. The control apparatus as recited in claim 2, wherein each of said cylinders further comprise an abutment for limiting the movement of said pistons with respect to said caps. 